Alt-click is not selecting edge loops in lInux
Alt key in most Linux window managers doesn't work properly with blender. You can configure it in various window managers, but the easiest solution for me is to shift+alt click. It will select an edge loop, but its in a "additive mode" so it works for selecting 1 edge loop, and continues selecting edge loops as if you are shift selecting multiple items.

Sorry if this text description is confusing, but try shift+alt click on the edge loop and it should achieve what you want.